Add support for working out IPPD based on LIDAR tiles

2017-06-01 18:54:49 +01:00
parent ee67a86a9f
commit 83cdc915d2
3 changed files with 277 additions and 104 deletions
--- a/tiles.cc
+++ b/tiles.cc
@@ -0,0 +1,113 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include "tiles.hh"
+#include "common.h"
+
+#define MAX_LINE 25000
+
+int tile_load_lidar(tile_t *tile, char *filename){
+	FILE *fd;
+	char line[MAX_LINE];
+	int nextval;
+	char *pch;
+	int w, x, y;
+
+	/* Clear the tile data */
+	memset(tile,0x00,sizeof(tile_t));
+
+	/* Open the file handle and return on error */
+	if ( (fd = fopen(filename,"r")) == NULL )
+		return errno;
+
+	/* This is where we read the header data */
+	/* The string is split for readability but is parsed as a block */
+	if( fscanf(fd,"%*s %d\n" "%*s %d\n" "%*s %lf\n" "%*s %lf\n" "%*s %lf\n" "%*s %d\n",&tile->width,&tile->height,&tile->xll,&tile->yll,&tile->cellsize,&tile->nodata) != 6 ){
+		fclose(fd);
+		return -1;
+	}
+
+	tile->datastart = ftell(fd);
+
+	if(debug){
+		fprintf(stderr,"w:%d h:%d s:%lf\n", tile->width, tile->height, tile->cellsize);
+		fflush(stderr);
+	}
+
+	/* Set the filename */
+	tile->filename = strdup(filename);
+
+	/* Perform xur calcs */
+	// Degrees with GDAL option: -co "FORCE_CELLSIZE=YES"
+	tile->xur = tile->xll+(tile->cellsize*tile->width);
+	tile->yur = tile->yll+(tile->cellsize*tile->height);
+
+	if (tile->xur > eastoffset)
+		eastoffset = tile->xur;
+	if (tile->xll < westoffset)
+		westoffset = tile->xll;
+
+	// if (debug)
+	// 	fprintf(stderr,"%d, %d, %.7f, %.7f, %.7f, %.7f, %.7f\n",width,height,xll,yll,cellsize,yur,xur);
+
+	// Greenwich straddling hack
+	if (tile->xll <= 0 && tile->xur > 0) {
+		tile->xll = (tile->xur - tile->xll); // full width
+		tile->xur = 0.0; // budge it along so it's west of greenwich
+		delta = eastoffset; // add to Tx longitude later
+	} else {
+		// Transform WGS84 longitudes into 'west' values as society finishes east of Greenwich ;)
+		if (tile->xll >= 0)
+			tile->xll = 360-tile->xll;
+		if(tile->xur >= 0)
+			tile->xur = 360-tile->xur;
+		if(tile->xll < 0)
+			tile->xll = tile->xll * -1;
+		if(tile->xur < 0)
+			tile->xur = tile->xur * -1;
+	}
+
+	if (debug)
+		fprintf(stderr, "POST yll %.7f yur %.7f xur %.7f xll %.7f delta %.6f\n", tile->yll, tile->yur, tile->xur, tile->xll, delta);
+
+#ifdef _LOAD_TILEDATA
+	/* Read the actual tile data */
+	/* Allocate the array for the lidar data */
+	if ( (tile->data = (int*) calloc(tile->width * tile->height, sizeof(int))) == NULL ) {
+		fclose(fd);
+		free(tile->filename);
+		return ENOMEM;
+	}
+
+	size_t loaded = 0;
+	for (size_t h = 0; h < tile->height; h++) {
+		if (fgets(line, MAX_LINE, fd) != NULL) {
+			pch = strtok(line, " "); // split line into values
+			for (w = 0; w < tile->width && pch != NULL; w++) {
+				/* If the data is less than a *magic* minimum, normalize it to zero */
+				nextval = atoi(pch);
+				if (nextval <= -9999)
+					nextval = 0;
+				tile->data[h*tile->width + w] = nextval;
+				loaded++;
+				if ( nextval > tile->max_el )
+					tile->max_el = nextval;
+				if ( nextval < tile->min_el )
+					tile->min_el = nextval;
+				pch = strtok(NULL, " ");
+			}//while
+		} else {
+			fprintf(stderr, "LIDAR error @ x %d y %d file %s\n", x, y, filename);
+		}//if
+	}
+
+	if (debug)
+		fprintf(stderr,"Pixels loaded: %zu/%zu\n",loaded,tile->width*tile->height);
+#endif
+
+	/* All done, close the LIDAR file */
+	fclose(fd);
+
+	return 0;
+}